1. Field of the Invention
The present invention relates to residential and commercial electrical wiring systems and devices; and, more particularly, to an improved electrical junction box for electrically connecting an electrical receptacle device to an electrical wiring system.
2. Description of Related Art
State and federal building codes require that when a building is wired to provide electrical power therein, the wiring must be installed between the exterior and interior wall surfaces, beneath the floors, above the ceilings, and between the surfaces of interior walls. The electrical wiring is installed after the framing of the building is completed but before the walls are erected on either side of the frame. Where ever electrical outlets, ceiling fixtures, wall switches, or the like are desired within the building, an electrical junction box, usually made of plastic or similar non-conductive material for interior use or metal for some exterior applications, is mounted on a frame member and then connected to the wiring. When wall surfaces, such as drywall or plaster, are later installed, access to the junction boxes is achieved through appropriate openings cut into the wall surface. Thus, standard residential and commercial electrical systems comprise a plurality of electrical junction boxes, each of which provides electrical conduit or sheathed cable for connecting the wires of electrical receptacle devices, such as electrical outlets, switches, fixtures, or the like to the electrical wiring of the building. While conventional electrical systems and junction boxes function adequately and relatively safely, they admit a variety of interrelated limitations. Conventional electrical wiring involves connecting the circuit at a junction box by terminating the stripped wires at the electrical receptacle device such as an outlet, switch, light fixture, hard wired appliance or the like. Therefore, in order to complete the proper, flush-mounted wall installation of any electrical receptacle device, all of the many wires and connectors associated with connecting the particular electrical receptacle device to the electrical system must first be connected electrically to the device and then the device with the attached wires is mounted onto the junction box. If the power is not shut off while the electrical receptacle device is being connected to the electrical system, the installer may receive an electrical shock during the installation, because the junction box contains a plurality of open wires and wire connections that are easily accessible and therefore readily mis-connected by the novice installer, such as the homeowner attempting to install a simple light fixture or ceiling fan without the aid of a skilled electrician. Moreover, because the wires are usually crammed into the junction box very tightly, the wires are capable of short-circuiting and causing dangerous electrical fires.
Standard electrical practices create additional limitations associated with the fact that current electrical systems only permit switch control of fixtures and/or outlets when the particular fixtures and/or outlets are directly wired to the same junction box as the switch. In an effort to circumvent this disadvantage, multiple gang junction boxes have been developed for terminating several switches in a single location and thereby permitting comparatively convenient control of multiple fixtures or groups of fixtures. Further, since a building""s electrical circuits cannot be tested fully until after the walls of a building are erected, electrical connectivity errors or problems related to proper switch control of particular outlets and fixtures are frequent, especially in the case of multi-way switches, where more than one switch controls a single fixture or group of fixtures. These errors are costly and time-consuming to correct, as they require that the relevant portion of the interior wall surface be removed and reconstructed after the electrical error has been found and repaired.
It therefore would be advantageous to have an electrical junction box that permits convenient and simplified installation and removal of electrical receptacle devices in a plug and play manner. It would also be advantageous to have an electrical junction box wherein electrical wires from a building""s electrical system terminate at a set of terminal strips and lugs in a secure area of the box rather than directly on an electrical receptacle device connected to the junction box. It would be further advantageous to have a junction box that provides a pair of plug-and-play terminals into which electrical receptacle devices are readily and conveniently plugged for connection to a building""s electrical system. It would also be advantageous to have a junction box that provides a low voltage connector block adapted to provide for smart circuitry and a smart circuit communications path. It would also be advantageous to have a method for terminating and routing electrical wires such that full testing of the circuitry is possible prior to completion of the interior wall surfaces. It would also be advantageous to have a junction box that decreases the possibility of electrical shock. It would also be advantageous to have an electrical junction box that reduces the risk of electrical fire.
An electrical junction box now has been discovered that overcomes the above-described deficiencies of the prior art. The present invention provides an improved electrical junction box wherein the electrical wires from a building""s electrical system terminate at connectors or lugs on a set of conductive terminal strips in a secure area of the junction box housing rather than directly on an electrical receptacle device that is mounted within and electrically connected to the junction box. In accordance with the instant invention, an improved electrical junction box provides at least one set of plug-and-play electrical termini into which electrical receptacle devices plug directly without any need for additional hard wiring, stripping, pig tailing, or the like. In a preferred embodiment of the instant invention, all electrical wires have a connection terminus on lugs conductively connected to terminal strips in a secure, non-confined area of the junction box, thereby eliminating the need to twist and pig tail bare wire and reducing the hazard of electrical shock as well as the risk of electrical fire. The housing can therefore also contain at least one set of low voltage cables for actuating and or monitoring the function of the junction box to provide a xe2x80x9csmart circuitxe2x80x9d.
In accordance with the broad aspect of the invention, the improved electrical junction box comprises a housing which is adapted to be fastened or attached to a building structure. The housing contains at least two conductive terminal strips that are preferably located at the rear of the housing and are insulated one from the other by a non-conductive barrier. At least two terminal connecting lugs, which are attached in spaced apart relation along the conductive terminal strip, are in conductive communication with each conductive terminal strip. Preferably, the terminal connecting lugs on the conductive terminal strips provide termination points for the wire strands contained in a standard 600V sheathed cable. In another broad aspect, the housing contains at least one set of low voltage cables, which preferably terminates at a low voltage connector block, to provide monitoring and/ or controlling function to the junction box of the instant invention.
In accordance with the invention at least one outstanding female connector, conductively communicating with at least one conductive terminal strip, provides a plug-and-play electrical interface adapted to matingly and retentively engage a male connector on an electrical receptacle device which is adapted for electrically connecting an electrical appliance or fixture to the building electrical system through the junction box. The electrical receptacle device has at least one male connector for removably connecting and retaining the electrical receptacle device by retentive engagement of the male connector with the corresponding female connector. The electrical receptacle device can be an electrical receptacle unit, such as an electrical outlet, an electrical switch, a switched outlet, a controlling device, or the like. Alternatively, the electrical receptacle device can be an electrical receptacle adaptor in the case of an electrical appliance or fixture such as a light fixture, a ceiling fan, or the like. In the latter case, the electrical receptacle adaptor is hardwired to the electrical appliance or fixture, and the male connector (or connectors) on the electrical receptacle device is (are) removably inserted into the corresponding female connector (or connectors) on the conductive terminal strips within the junction box. Thus, when the male connectors of an electrical receptacle device are matingly and retentively engaged with or inserted into the corresponding female connectors, the male connectors are conductively connected to the conductive terminal strips in the junction box housing, which thereby electrically connects the electrical receptacle device to a building""s electrical power supply.
The junction box housing preferably is made from non-conductive material to which the conductive terminal strips are attached. The housing also can be made from conductive material, such as metal, which contains an insulating film or barrier along the rearward interior thereof to insulate the conductive terminal strips from the conductive housing.
In a preferred embodiment, the electrical junction box houses a set of at least three conductive terminal strips, including at least one electrically positive conductive terminal strip, at least one electrically negative conductive terminal strip, and at least one electrically neutral conductive terminal strip. In this preferred aspect, the junction box also has a corresponding set of at least three female connectors substantially aligned with each other and extending outwardly from the corresponding conductive terminal strips and adapted to removably, matingly, retentively, and conductively engage a corresponding set of at least three male connectors on an electrical receptacle device.
In another embodiment, the male connector on the electrical receptacle device is a single, medially insulated prong having a first side that is electrically positive and a second side that is electrically negative. In this embodiment, the single, medially insulated prong is removably, matingly, retentively, and conductively engaged with or inserted into a corresponding, medially insulated, female connector having a first side in conductive communication with an electrically positive conductive terminal strip and a second side in conductive communication with an electrically negative conductive terminal strip. The first and second sides or conductive portions of the medially insulated female connector are separated by and proximate to the medial insulative barrier. Thus, a single female connector engages a single male connector, each of which carries both the positive side and the negative side of the circuit.
In another embodiment, the electrical receptacle device has two male connectors, wherein one of the male connectors or prongs is electrically negative, and the other male connector or prong is electrically positive. In this embodiment, the two male connectors are removably, matingly, retentively, and conductively engaged with or inserted into a corresponding set of two female connectors which conductively communicate with two corresponding conductive terminal strips. One of the conductive terminal strips is electrically positive, and the other conductive terminal strip is electrically negative.
In a preferred embodiment, a security plate having apertures substantially corresponding to the female connectors fits over the female connectors for removable attachment within the interior of the housing to provide a secure, substantially enclosed environment within the rear portion of the junction box. Thus, all open electrical contacts within the junction box are separated from the remaining portion of the electrical junction box.
In accordance with another aspect of the invention, the housing contains at least one set of low voltage cables which preferably passes through the housing and terminates at a low voltage connector block. Preferably, the low voltage cables comprise two matched sets of cabling, one for control of the circuit and the second for monitoring activity therein. The low voltage connector block is adapted to receive a control/monitor pigtail from an electrical receptacle device mounted on and electrically and/or conductively connected to the electrical junction box, thereby facilitating a smart circuit communications path. When a control or monitor capable electrical receptacle device having a control/monitor pigtail is removably inserted into the junction box, the control/monitor pigtail removably interfaces with the low voltage connector block such that a xe2x80x9csmart circuitxe2x80x9d is capable of completion. In accordance with this embodiment, the housing is preferably partitioned to separate the low voltage cable and/or the low voltage connector block from the other components of the junction box. Preferably, the partition is a non-conductive, low voltage barrier. In a preferred aspect, the at least one set of low voltage cables is two sets of low voltage cables; a first set communicates data and information to the low voltage connector block and a second set is used for controlling and monitoring the electrical receptacle device or devices electrically and/or conductively connected to the junction box. In another preferred embodiment, the low voltage connector block is enclosed behind the above-described security plate and is therefore contained within a rearward side portion of the junction box. In this preferred aspect, the security plate further comprises at least one aperture that substantially corresponds to at least one aperture on the low voltage connector block that is adapted to receive the control/monitor pigtail. Thus, when the security plate encloses the low voltage connector block in a rearward side portion of the junction box housing, the control/monitor pigtail can removably and matingly engage the low voltage connector block through the security plate.
In accordance with the invention, a plurality of electrical junction boxes, each electrically connected to particular electrical receptacle devices, can be wired in series. The present invention provides for identical wiring of all electrical receptacle devices capable of being connected to the improved junction box regardless of the type of electrical receptacle device. Each electrical device or unit includes an identically wired electrical receptacle device having at least one male connector which is matingly engaged with or plugged into a corresponding female connector within an electrical junction box. In a preferred embodiment, each junction box is then wired in series with other similar junction boxes, providing for up to eight non-switch electrical receptacle devices on a single circuit. In a preferred embodiment, when the electrical junction boxes are wired in series, standard 600V sheathed cable enters the junction box through an end panel of the housing, connects to the conductive terminal strips by means of spaced apart lugs, and exits the junction box through an opposing end panel of the housing for continuation of the electrical circuit and connection to the next junction box in the series. Similarly, in another preferred embodiment, the low voltage cables enter the junction box through an end panel of the housing, connect to the low voltage connector block, and exit the junction box through an opposing end panel of the housing for continuation of the smart circuit and connection to the next junction box in the series.
Other objects, features, and advantages of the present invention will become apparent to those skilled in the art from the following detailed description. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given for purposes of illustration and not of limitation. Many changes and modifications within the scope of the present invention may be made without departing from the spirit thereof, and the invention includes all such modifications.